Audi straight five

Audi’s development of four-wheel drive from a military truck to rally stages is well documented, but the Quattro’s 2.1-litre five-cylinder engine had more prosaic beginnings, starting life in Audi saloons with 170bhp. For the rally coupé, it gained a further 30bhp, giving 0-60mph in 7.1sec and 137mph in 10-valve form. To qualify for the World Rally Championship, it had to be reduced in capacity from its normal 2144cc to 2133cc, but it gained four valves per cylinder and a KKK K27 turbo for 300bhp at 6700rpm. The later A1 and A2 versions produced 350bhp, while the Sport had 444bhp. Its final fling came with the 473bhp S1 E2 Quattro that arrived just ahead of the Group B class being banned after a series of fatal crashes.